For me having a 95 gallon aux tank in addition to the 28 gallon tank is a big help.
#1 it allows me the freedom to pick and choose a station based on ease of navigating the pumps and price. I will never save enough money to pay back the cost of the tank but that is not the reason I got the tank.
#2 In SC fuel is cheap so I start of full. Land is also cheap so the stations usually have more room to maneuver. There are stations in NJ where land is more expensive and consequently the room to maneuver is so poor that have to disconnect the RV from the truck to be able to maneuver,and that is where having an AUX pump comes in handy, I can fill up from my own tank at any Wally world parking lot or rest stop.
#3 with 120 gallons of fuel I have a range of well over 1,000 miles which means that if I really want to stretch out the distance between fill ups I don't have to start looking for fuel till I have traveled at least 800 miles.
One thing that may be helpful is try to fill up your truck after you pull into a campsite. If I am staying at a campsite I will unhook and do sight seeing run errands then the last thing I do before I am ready to leave the camp site is to fill up my truck
The pump is not hooked up the battery, I use jumper cable clips when I need to pump fuel.
I use a gun cable lock on the nozzle to impede fuel theft, it has and auto shut of. It list for $400 but I paid a lot less at the store (it was on sale). You can save over $100 by getting a non auto shut off nozzle.
At 15 gallons per minute it take about 90 seconds to fill up the tank. I keep a stopwatch and time the pump I deduct 15 gallons for each 60 seconds and deduct that amount from the 95 gallon capacity which gives me a close estimate of how much fuel is remaining in the tank.
You will save some money by being able to buy fuel in a state where it is cheaper but it will never pay for itself the reason I got it was connivence and piece of mind knowing I had a rane of well over 1,000 miles
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2014 4 WD Silverado 403 CI diesel long bed dually, B&W hitch with 95 Gallon Auxiliary Fuel Tank, pulling a 33 foot Holiday Rambler Alumascape suite, Winegard SK-3005 TRAV'LER slimline dish, Splendide 2100 XC washer dryer, TST Tire Pressure monitor system.